Control means for internal-combustion engines



Aug. 25, 1953 R. MILLER CONTROL MEANS FOR INTERNAL-COMBUSTION ENGINESFiled July 51, 1948 m fliiarvzeys.

Patented Aug. 25, 1953 CONTROL MEANS FOR INTERNAL- COMBUSTION ENGINESRalph Miller, Milwaukee, Wis., assignor to Nordberg ManufacturingCompany, Milwaukee, Wis., a corporation of Wisconsin Application July31, 1948, Serial No. 41,794

9 Claims.

My invention relates to an improvement in control means for internalcombustion engines and has for one object to provide heat responsivemeans for controlling the inflow of scavenging air.

Another object of my invention is to provide means responsive to exhausttemperatures for controlling the rate of air flow to the combustionchamber.

7 Another object is to provide an improved air control valve andactuating means therefor.

' Another object is to provide an improved means for locking the aircontrol valve in advanced position.

Another object is to provide an improved heat responsive assembly foractuating the air flow control valve. 1

Other objects will appear from time to time throughout the specificationand claims.

In internal combustion engines, and particularly in engines of the gasdiesel type, it is advantageous to reduce the quantity of air which istaken into the cylinder when the load is reduced, so that the air-fuelratio at all loads will remain substantially constant. When the air isthus regulated with the load, it is found that the exhaust gastemperature remains substantially constant at all loads. I provide meansand a method of controlling and regulating the air flow to thecombustion space during the suction stroke in such a manner as tomaintain a substantially constant exhaust temperature. It is known thatas the air-fuel ratio is reduced, the exhaust gas temperature increases.Conversely, the exhaust gas temperature decreases as the air-fuel ratioincreases.

My invention is illustrated more or less diagrammatically in theaccompanying drawing which shows a sectional view through an engineembodying my invention.

Like parts are indicated by like characters throughoutthe specificationand drawings.

Referring to the drawing, I is a cylinder, 2 a piston mounted forreciprocation therein, 3 a cylinder head. 4 is an exhaust valve, 5 anintake valve, 6 a spray nozzle for liquid fuel, I a gas fuel supplyvalve. 8 is the exhaust passage leading from the exhaust valve 4 to theexhaust pipe 9. I is a bulb housing in the exhaust pipe 9 whose purposewill hereinafter appear. I I is the intake passage communicating withthe intake valve adapted to receive scavenging air through the'airscavenging control valve I2, the airbeing supplied by a pressure passageI3 from any suitable source ofscavenging air. v

In the bulb housing I0 is a bulb I4 adapted to contain mercury or othersuitable heat expansible liquid or fluid. I5 is a conduit leading fromthe bulb I4 to the expansible motor bellows I 6. I1 is a piston rodactuated by the bellows I6 in response to pressure generated in the bulbI4 adapted to actuate the balance piston l8 in the motor cylinder I3.

is a pipe communicating with the interior of the cylinder between theheads 2| and 22 of the balanced piston valve. It receives hydraulicfluid under pressure from any suitable source not here illustrated. 23,24 are exhaust pipes leading from the opposed ends of the cylinder I9.25, 26 are hydraulic fluid pipes each communicating at one end with thecylinder I9 and communicating at the other end with a motor cylinder 2!containing piston 28. The pipe 25 communicates with the cylinder on theunderside 'of the piston 28, the pipe 26 communicates with the pipe onthe upper side of the piston 28.

29 is a piston rod connected by means of linkage 33 to the valve stem 3|of the control valve I2. As indicated in this particular exemplificationthe control valve stem 3| carries two inclined valve discs 32 movabletoward and from apertures 33 in valve walls 34 so that with the parts inthe position shown, the valves 32 are partly unseated and movement ofthe valve stem 3| will open and close said valves between their workinglimits. 35 is a fixed aperture not under control of the valves.

With the parts in the position shown in th drawing, the piston 28 ishydraulically locked against movement because the two ends of the pipes25 and 26 are closed by the piston heads 2I and 22. If the temperaturein the exhaust pipe changes it will cause movement of the balanced valveI9 in one direction or the other. If the temperature increases, thecontents of the bulb I4 will'expand, the valve I8 will move to theright. If temperature decreases, the valve will move to the left.

If the valve I8 moves to the right in response to an increase intemperature, hydraulic fluid entering into the pipe 20 will as the head22 uncovers the end of the pipe 26 pass down through the pipe 26,tending to move the piston 28 upwardly. At the same time, however, thepiston head 2| will have opened the pipe 25 to permit hydraulic fluid tobe forced from above the piston 28 out through the pipe 25 anddischarged through the pipe 23. This tends to open the valve I2 toincrease the amount of scavenging air admitted to the engine and thissituation will continue until the temperature in the exhaust pipe fallssufliciently to cause the bulb [4 to cool enough to move the piston [3back to the central locking position at which time the valve 33 will belocked in proper position.

If on the other hand the temperature in the exhaust pipe falls, theopposite cycle of events takes place. Pressure is introduced through thepipe to lower the piston 28 While hydraulic fluid escapes through thepipes 26 and 24.

Thus slight temperature variations in the exhaust are immediatelycompensated for by adjustment of the valve l2 and as soon as theadjustment has taken place and the valve l2 has sought a new positionconforming to the changed engine conditions Which result in properexhaust temperature the valve is automatically locked in properposition. Of course, the opening always permits the introduction of aminimum of scavenging air no matter what the valve position.

The link 39 is a two-part link, the two parts being joined by a nut isin which the two ends of the link are oppositely threaded. The nut 4E]carries on its outside periphery thereof a gear 41 in mesh with a rackQ2 adapted to be reciprocated by the governor of the engine or by anyother suitable means not herein shown forming no part of the invention,for the purpose of changing the relative positions of the work piston 28and the valve 33.

It will be realized that whereas I have described and shown an operativedevice, still many changes might be made in the size, shape, number andarrangement of parts without departing materially from the spirit of myinvention. I wish, therefore, that my showing be taken as in a broadsense diagrammatic and illustrative rather than limiting me to theprecise show- The use and operation of my invention are as follows:

The parts as illustrated are in for example such position that the airfuel ratio will cause the engine to operate at exhaust temperature of'750 degrees F. though of course other temperatures might be desirable.The piston 28 can move freely in the work cylinder 21 from end to endthereof depending on where the pressure is applied. The piston valve l8is free to reciprocate in the cylinder l9 under the influence of thebellows I6 which translates change in temperature as applied to the bulbI l into movement of the control piston [8.

The control mechanism is shown in position for a steady condition, whichmay for example be one-half load, and an exhaust temperature, let us sayof 750 degrees F. The valve 33 is held in the position shown in thedrawing by the piston 28. The piston 28 is locked with hydraulic fluidat each side and with the connections between the work cylinder 2? andthe control cylinder I9 closed by the lands of the piston. If now theload on the engine increases, the engine governor, which is not hereinshown, willadmit more fuel to the combustion chamber of the individualcylinders. The immediate result is to increase the exhaust gastemperature, because the valve 33 is set to position the quantity of airsuitable for half load. In response to the increase in exhausttemperature, the bulb it causes a movement to the right of the bellowsl6 referring to the position of the parts in the drawing. This moves thepiston l8 to the right, uncovering the port of the passage 25. Fluid canthereby flow from the left-hand end of the control cylinder [9 and bedischarged from the discharge passage 23 to the atmosphere. The port ofthe passage 26 is simultaneously opened to the inner space between thetwo piston lands, which i supplied with fluid under pressure from thepipe or duct 20. Thus pressure fluid is free to flow along the duct 26to the lower side of the piston 28, in the work cylinder 2?, and thepiston 28 will thereby be moved to further open the valve 32, to admitan increased air supply to the combustion space. This increase in theair quantity causes a reduction in the exhaust ga temperature in thepipe 9 and the exhaust manifold. The temperature responsive mechanism,including the bulb M, will therefore be actuated to move the piston tothe left, to close the ports of the passages 25 and 26. As soon as thishas taken place, the piston 28 is locked in the position in which it isset. The piston 28, being locked or fixed, will hold a valve 32 in aposition which will produce the predetermined exhaust temperature in theexhaust manifold.

Any increase or decrease in the exhaust temperature will similarly causethe work piston to hunt for its proper position and when the work pistonreaches its proper position, it is then locked in the proper setting bya return movement of the control piston into position to close thepassages between the two cylinders.

By introducing any suitable compensating device between the heatresponsive structure and the work piston, operated for example by theengine governor, any other desired load temperature relation can beautomatically produced.

I claim:

1. The combination of an internal combustion engine having a combustionchamber, a combustion air passage extending thereto, and an exhaustpassage extending therefrom: air compressing means for supplyingcharging air to said combustion air passage; a valve member between theair compressing means and the engine cylinder valves formed and adaptedto vary the effective air admitting diameter of said combustion airpassage; a heat responsive member positioned to respond to the heat ofsaid exhaust passage; and an actuating connection between said heatresponsive member and said valve member adapted to adjust the positionof said Valve member in response to heat conditions in said exhaustpassage, and to lock it in adjusted position.

2. The combination defined in claim 1, in which the actuating connectionincludes an expansible fluid containing member.

3. The combination defined in claim 1, in which the actuating connectionincludes a cylinder, a piston therein, connected to said valve, a sourceof fluid pressure, and connections between said source of fluid pressureand said cylinder, at each side of said piston.

4. The combination defined in claim 1, in which the actuating connectionincludes a cylinder, a piston therein, connected to said valve, a sourceof fluid pressure, connections between said source of fluid pressure andsaid cylinder, at each side of said piston, and a control assembly,responsive to said heat responsive member, formed and adapted to closesaid connections when the valve member is in a position appropriate tothe temperature conditions in the exhaust passage.

5. The combination defined in claim 1, in which the actuating connectionincludes a power cylinder, a piston therein, connected to said valve, asource of fluid pressure, connections between said source of fluidpressure and said power cylinder, at each side of said piston, and acontrol assembly, including a control cylinder connected to said sourceof fluid pressure, a piston in said control cylinder, an actuatingconnection between said piston and the heat responsive member, and fluidpassages between said cylinders.

6. In a control assembly for internal combustion engines having an airinlet passage and an exhaust passage, a heat responsive memberresponsive to the heat of gases in the exhaust passage, a valve formedand adapted to control the rate of flow of air through the air inletpassage, and an actuating connection between the heat responsive memberand the valve, adapted to set the valve at the proper position to supplythe air necessary to maintain a predetermined exhaust temperature, saidactuating connection including a portion formed and adapted to lock thevalve in adjusted position when the heat responsive member is satisfied.

7. The combination defined in claim 6, in which the actuating connectionincludes a master cylinder and a work cylinder, a iston in the workcylinder connected to the valve, fluid passages between the mastercylinder and the opposite ends of the work cylinder, a pressure passageto an intermediate part of the work cylinder from a suitable pressuresource, exhaust passages from opposite ends of the work cylinder and apiston in the work cylinder connected to the heat responsive member.

8. In an internal combustion engine, an intake passage, an exhaustpassage, a charging valve independent of the engine for controlling theefiective area of the intake passage and so the amount of charging airadmitted, a hydraulic motoradapted to positively control the chargingvalve, a motor control valve, a hydraulic circuit including the motor,control valve and the charging valve motor, a heat sensitive element inthe exhaust passage and an actuating connection between the heatsensitive element and the control valve whereby the charging valve isactuated responsive to variations in exhaust temperature.

9. In an internal combustion engine, an intake passage, an exhaustpassage, a charging valve independent of the engine for controlling theeffective area of the intake passage and so the amount of charging airadmitted, a hydraulic motor adapted to positively control the chargingvalve, a motor control valve, a hydraulic circuit including the motor,control valve and the charging valve motor, a heat sensitive element inthe exhaust passage and an actuating connection between the heatsensitive element and the control valve whereby the charging valve isactuated responsive to variations in exhaust temperature, means formaintaining the hydraulic system constantly filled with hydraulic fluidwhereby the charging valve is locked in the position in which it isplaced responsive to the heat sensitive element.

RALPH MILLER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,856,024 Biichi Apr. 26, 1932 2,040,778 Morgan May 12, 19362,248,090 Kittler July 8, 1941 2,389,797 MacNeil et :al Nov. 27, 19452,426,740 Mock Sept. 2, 1947

